DESCRIPTION OF THE PLATES 263 



PLATE X 



FIG. 



1. Chermes strobilobius, larval fundatrices on bud of Picea excelsa. {i.) 



2. Buds of Picea excelsa, with galls caused by Chermes strobilobius. {{.) 



3. Third-year shoot of Larix eurofaea, as seen at the end of March, 



with larvae and eggs, one larva at base of each bud. (f.) 



4. Larva and eggs. (}.) 



5- Eggs of exules on leaf of Larix europaea. (f.) 



6. Eggs of sexuparae on ditto, (f.) 



7. Part of shoot of Larix europaea, with colonic!, exules, and winged 



sexuparae. (^.) 



8. Exule with pupal skin, (f.) 



9. 10. Winged sexuparae. (J.) 



PLATE XI 



An apple-tree branch, with numerous tumours associated with 

 Myzoxylus laniger (=Schizoneura lanigera). (^.) 



PLATE XII 



1. Galls on leaflets of Fraxinus excelsior, caused by the presence of 



PsyUofsis fraxini, showing at (a) early state, (6) mature gall, {c) 

 appearance of leaflet after departure of the insects, (f.) 



2, 3, 4. Psyllopsis fraxini. (f.) 



5. Leaves of Populus nigra, with galls caused by Pemphigus affinis, 



showing at (d) early, and («) mature galls. (|.) 



6. Galls on twig of Po/iMte nigra, caused hy Pemphigus bursurius (f.) 



7. Pemphigus bursarius, apterous viviparous ? . (|-.) 



8. Ditto, pupa, (f.) 



g. Leaf of Populus nigra, with its petiole galled by Pemphigus spiro- 

 thecae. (^.) 



10. Pemphigus spirothecde, a.'pt.eioMs vWi-paxaas $. (f.) 



PLATE XIII 



1. 'Lsa.iolAcer psendo-platanus, with galls caused by Eriophyes macrorrhyn 



chus. (J.) 



2. Two galls, (f.) 



3. Section of a gall. {^.} 



4. Aperture of gall of E. macrorrhynchus on lower surface of leaf, (f.) 



5. Unicellular hair from gall of £. MiacfWJ'AyMcAMs. (^.) 



6. Eriophyes macrorrhynchus. mK) 



7. Leaf of Acer campestre, with galls caused by Eriophyes macrorrhyn- 



chus. (i.) 



8. Galls in various stages of development, (f.) 



9. Section through three galls and midrib of the leaf, (f.) 



10. Aperture (lower surface of leaf) of three galls, (f.) 



11. Leaf of Acer campestre, with two galls caused by Eriophyes macrp- 



chelus. {}.) 



12. Gall, a.) 



13. Section of gall. (J.) 



